Return smoke eliminator for domestic stokers



Sept 1933. L. L..H|NSCH 1,925,249

RETURN SMOKE ELIMINATOR FOR DOMESTIC STOKERS Filed Sept. 15. 1930.

1 INVENTOR/ BYW-L 46 ATTORNEY Patented Sept. 5, 1933 S T A E Q;

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RETURN ST/EQiKE ELHIJUINATQDR lFiUBR lIMMl/HESTIIC SMOKERS poration of (thin Applicaticn September 15, 119% Serial No. 462,144

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This invention relates to new and useful improvements in return smoke eliminators for doniestic stokers.

It is the principal object of my invention to provide means to prevent the discharge from the coal feed pipe of a furnace or boiler, of the fumes and smoke which result from an over supply of fuel being fed into it. The common experience has been to find that when an excess amount of a combustible substance such as green coal is underfed into a furnace or boiler, the air that enters around the retort is sometimes choked by this 'over supply of fuel; and in some cases finds its least resistance back through the coal feed pipe, permitting the fumes and smoke to be discharged into the basement.

In the accompanying drawing illustrating my invention, Figure 1 is a side view of a domestic stoker to which my return smoke eliminator is applied. And Figure 2 is an end view thereof, the conveyor tube and worm being shown in section.

Referring to the accompanying drawing for a detailed description of my invention, the stoker illustrated therein includes a gear box 1 into which there projects the armature shaft 2 of an electric motor 3. On the opposite end of the shaft 2 a forced draft fan 5 is secured within a housing 6. The suction of this fan is controlled by a disc plate damper 7 formed with a tapped axial hole that fits a threaded axial rod 8 which projects outwardly from the fan housing 6. Through an outlet 9 the fan housing 6 communicates with the retort of the furnace.

The numeral 10 designates the hopper which a right angled pipe or duct 11 enters at the point 12. The other end of this pipe is received by a tubular projection 13 on the fan housing 6. The pipe 11 projects nearly half way into the hopper 10, to the opening 14, through which fuel descends to a conventional conveyor tube 15.

Secured within the hopper casing 10, and extending from one side of the latter to the other, over that section of the suction pipe 11 which projects into said casing, is a bafiie partition 16. The latter is inclined outwardly from top to bottom to provide a suction chamber between its free lower end and the hopper casing wall to which it is attached. The fuel in the hopper 10, on account of covering the plate 16 and filling the hopper to a considerable depth above the plate 16, acts to seal said suction chamber from the external atmosphere.

Rotatable within the conveyor tube 15 is a conventional worm 17. When the air that enters the retort is choked by an over supply of green coal (G11. lit -149%) fed onto the grate (not shown), the fumes and smoke will travel back through the conveyor tube 15 between the wall of the latter and the worm 17, to enter the basement or other place wherethe furnace or boiler is located. To prevent this, my invention provides that the smoke, at the point 16 where the greatest suction is exerted upon it by the suction pipe 11, will be drawn into the latter and through it. to the fan housing 6. From the latter the smoke is discharged through the outlet 9 into the retort.

The withdrawal by suction from the hopper 10, of the smoke and fumes which enter it from the conveyor tube 15, prevents their discharge into a basement or other place where the furnace or boiler which the hopper serves, is located.

Having described my invention, I claim: 1. In stoker apparatus, the combination with v the fuel hopper and conveyor tube for conveying the fuel from the hopper to the furnace in which it is burned, of suction-creating means, a plate in said hopper directly above and adjacent the opening from the hopper into the conveyor tube and forming a space to receive gases flowing backward through the conveyor tube to the hopper, and 30 means connecting said space with said suctioncreating means and whereby the gases will be withdrawn from said space.

2. In stoker apparatus, the combination with I the fuel hopper and conveyor tube for conveying the fuel from the hopper to the furnace in which it is burned, of suction-creating means, a plate in said hopper directly above and adjacent the opening from the hopper into the conveyor tube and forming a space to receive gases flowing backward through the conveyor tube to the hopper, and a duct connecting said suction-creating means with said space at a pointdirectly above said opening and whereby the gases will be withdrawn from said space.

' LOUIS L. HINSCH. 

